What if you don’t already have their app. Then there is friction. I am about 20 feet away from a Bird scooter but under the present circumstances I’m not interested in creating an account, etc.
For others, I think if you have competent product people, you'd limit registration to a phone number and offer apple/android pay. With iOS 12, for example, it would be so seamless since it can auto-fill confirmation codes. So all you'd have to do is put in your phone number and you're logged into a new account.